Urine Chemical and Physical tests

based on color, clarity, odor, viscosity, and sweetness

1827

180,000 mL plasma filtered in kidney daily

1200 mL

95% water, 5% solutes

urea (protein amino acid breakdown)
also has inorganic chloride, sodium, and potassium

urea and creatinine levels

cells, crystals, and bacteria

600 to 1800 mL / day

the inability of kidneys to change specific gravity of plasma (stays at 1.010 regardless of hydration)

urochrome (urobilin)

comes from urobilinogen; urobilin is a lipid-soluble pigment in plasma excreted in urine

light yellow, yellow, amber, red, brown

blood or myoglobin
bilirubin
porphyrins
melanin
homogentisic acid
ingested substances

muscle atrophy that leads to myoglobin in urine

medication, dyes, vitamins, pigmented foods

protein
(yellow foam = increased bilirubin)

1. contamination from skin or vaginal secretions, bacteria, or fecal material
2. precipitation of dissolved solutes, x-ray contrast media
3. RBC, WBC, epithelial, clots, bacteria, casts

because of bacterial conversion of urea to ammonia

ingestion of certain food or drugs

ketones (fruity smell) and branched-chain amino acids in MSUD

because of the ketones causing fruity smell
Diabetes : cells are starving (bc cant get glucose) -> has to break down lipids and fats instead -> ketones are released

mass of solutes present per volume of solution ;
both number of solute and molecular size affect specific gravity

distilled (pure) water

density of urine / density of equal volume of pure water

Measurement of light from air passed into a solution at an angle, refracting off solutes

275 to 900 mOsm / kg

275 to 300 mOsm / kg

body is able to filter and adjust for osmolality (kidneys)

diet, fluid intake, and physical activity

1. evaluate renal concentrating ability
2. monitor renal disease
3. monitory fluid and electrolyte balance
4. differentially diagnose cause of polyuria

measured by using colligative properties of solution (like freezing point and vapor pressure) and compared to DI water

oxidation or reduction of metabolites

bacterial growth and precipitation of amorphous material

bacterial multiplication causing breakdown of urea to ammonia

breakdown of urea to ammonia by urease producing bacteria or loss of CO2

glycolysis and bacterial use

volatization and bacterial metabolism

exposure to light

oxidation to urobilin

multiplication of nitrate-reducing bacteria

disintegration in dilute alkaline urine

multiplication of bacteria

loss of motility, death

RBC breakdown -> bilirubin -> carried by albumin to liver -> conjugated (direct) bilirubin -> mix with bile -> goes to GI tract and mixes with bile and GI bacteria to make UROBILINOGEN -> urobilinogen gets reabsorbed back into body -> some goes back to kidney where it becomes urobilin (urine color)

prevents bacterial growth and metabolism

excellent sediment preservative

drug analysis, maintains integrity of drug over a longer time

qualitative results based on color change

ascorbic acid (vitamin C)

to confirm results obtained from test strip, confirm pigmented urine

ictotest

to find protein other that is not detected from protein strip
(protein strip only detects albumin!)

acetest

ionic solutions (Na+, K+, Cl-, NH4+); the strip does not detect glucose

4.5-8.0, usually slightly acidic but more alkaline after meals

saturation point of solutes

double indicator : bromothymol blue and methyl red

hematuria (not distinct) and hemoglobinuria (uniform)

pseudo peroxidase reduces peroxide of blood, chromogen is oxidized

ascorbic acid (vitamin C)

>20 WBC/ uL

measures leukocyte esterase released by WBC instead of WBC because WBC gets lysed too quickly

leukocyte esterase cleaves ester in pad

allergy (eosinophils) or bacteria (neutrophils)

nitrate-reducing bacteria present

WBC because usually with infection (bacteria) there should be WBC that are fighting

1. bacteria must be nitrate reducers
2. adequate time in bladder to be reduced

proteinuria

specifically albumin

detect minute (<1 to 2 mg/dL) of albumin
screens diabetic patients for early kidney damage

when plasma glucose level is over 160 to 180 mg/dL

glucose oxidase in pad oxidizes glucose to form hydrogen peroxide and gluconic acid

cannot detect other sugars and carb metabolism disorders (like galactosemia)

benedicts copper reduction

sugars (except sucrose), ascorbic acid, cysteine, and some drugs
-> galactosemia!

acetoacetate, acetone, (B-hydroxybutyrate, not detected but compounds interchange between each other)

from the breakdown of fat and lipid metabolism

conjugated bilirubin (water soluble, conjugated from the liver)

hemolytic anemia and liver cirrhosis and hepatitis

usually because there is too much breakdown of blood (hemolysis) and the liver works fine, causing the excess to be wasted in urine

in the alkaline tide, 2 hours after eating